The present invention relates to an internal combustion engine, more particularly to an internal combustion engine which has a plurality of cylinders differently used for starting and operation.
Internal combustion engines of the above mentioned general type are known in the art. One such internal combustion engine is disclosed, for example, in German Auslegeschrift DE-AS No. 2,454,829. In this internal combustion engine, at least one cylinder is used for receiving exhaust gases produced from combustion in at least one other cylinder. This cylinder is directly connected by its inlet conduit to an outlet conduit of the other cylinder. The cylinder which is determined for receiving the exhaust gases has another dimension for its combustion chamber and a higher compression ratio than the other cylinder. When the internal combustion engine is designed in accordance with this construction, a returnd part of the exhaust gases from the working cylinders is cooled regardless of the outer cooling system to a damage-reducing temperature and makes possible easy starting of this engine.
Another known internal combustion engine of this type is disclosed in German Offenlegungsschrift DE-OS No. 2,325,060 and has two cylinder groups, of which one cylinder group is used for starting and the other cylinder group is used for operation with a normal engine efficiency. It provides for good starting ability with a high efficiency and reduced mechanical loading. Both the above described constructions have the tendency to make the diesel engines ready to start, on the one hand, and do not excessively increase the combustion values to reduce the yield of carbon dioxide, on the other hand. All these features are not suitable to provide for equally good utilization of the fuel in all operational conditions. In particular, the Otto engines show the disadvantage in that they have, in the partial loading region, a low temperature of the fuel-air mixture at the end of the compression stroke. The ignition and the combustion are thereby poor. The fuel is not used in optimal manner. The known filling of the combustion chamber by charging improves the combustion considerably in the full-load region.